$\begin{cases}d(1)=8\\\\ d(n)=d(n-1)\cdot (-5) \end{cases}$ What is the $3^{\text{rd}}$ term in the sequence?
Answer: This is a recursive formula. It tells us that the first term is $8$ and that the common ratio is $-5$. $\begin{aligned} {d(1)}&=8 \\\\ {d(2)}&={d(1)}\cdot (-5)=-40 \\\\ {d(3)}&={d(2)}\cdot (-5)=200 \end{aligned}$ The $3^{\text{rd}}$ term is $200$.